My guppies are stressed?

Question
Hi John,

I've got a 10 gallon aquarium.  A bunch of them just had a ton of babies and they are all growing into normal sized fish.  Right now there are 3 baby fry, 4 fish that are growing and 10 regular sized fish and 3 pregnant fish, 2 bottom feeders and one plecho (sp?)that i just bought yesterday.  I understand that that's a lot of fish for a ten gallon tank and will be passing some off to friends...actually this afternoon.

Anyway, I woke up this morning and found a bunch of them (7) in one corner shaking (mix of sizes), the other half swimming normally.  The ones in the corner are shaking/vibrating and staying right to the bottom resting on the rocks.  They'll all move around a bit, swim around the tank for a second or two and then back to the corner again.  Is it because they are stressed, too crowded or sick?

I changed out a third of the water today, changed the filter and added cycle to the tank.  There is a lot of algea, but the plecko is there now...

any suggestions?

Answer
WAY overstocked! A pleco needs 55 gallons as a minimum and the guppies will need 75 gallons soon.

They are dying from toxic materials like ammonia, nitrite, and nitrate in the water that has built up.

Cycle does nothing, by the way. It is a marketing ploy that does not actually help the aquarium at all. You just need dechlorinator. I suggest Seachem's Prime.

John Kliewer